After redistricting, incumbent Democrat Tom E. Shanahan of Georgia's 10th House District decided to retire. Graves won the open seat with 60% of the vote.[3] After mid-decade redistricting, Graves decided to run for Georgia's 12th House District, vacated by Republican Jeff Lewis who decided to run in the 15th District. Graves won unopposed in 2004.[4] He won re-election unopposed in 2006[5] and 2008.[6]

In May 2010, Graves won a special election to replace Republican US House Representative Nathan Deal.[9] On June 8, 2010, Graves won the run-off for the special election against former state Senator Lee Hawkins.[10] Graves then faced Hawkins two more times, in another primary election and run off before winning the November 2, 2010 general election unopposed. [11][12] Upon his election, Graves joined the House Republican Whip team,[13] which he later left in 2011.[14] In January 2013, Graves rejoined the Whip team, and is a member as of 2014.[13]

Representative Graves’ home in Ranger was drawn into the newly created 14th district during the 2012 census, and as a result, he elected to run as Representative for the newly created district.[15] Graves won the November 6, 2012 election against Democratic challenger Daniel “Danny” Grant with 73 percent of the vote.[16]

Representative Graves is a pro-life politician and voted in 2011 to limit funding to Planned Parenthood.[17] He has stated that he opposes abortion "without exception", including when the mother's life is at stake.[18]

Graves was endorsed by the Atlanta Tea Party in 2010.[19] He authored the Defund Obamacare Act in 2010 and reintroduced the bill in the 112th and 113th Congress.[20]

Graves co-sponsored a balanced-budget amendment in both the 112th and 113th Congresses and supported the Cut, Cap and Balance Act of 2011, which aimed to reduce federal spending and establish caps in future spending.[14] The same year, Graves introduced the HOME Act to allow Americans to make withdrawals from their retirement accounts to pay timely mortgage payments in 2011.[21] He also voted against removing US troops from Afghanistan in March 2011.[22] Graves introduced the Transportation Empowerment Act (TEA) in 2011, meant to lower the federal gas tax to 3.7 cents per gallon and transfer nearly all funding authority to U.S. states over a period of five years.[23] Graves voted in favor of the Water Resources Reform and Development Act in 2013, which funded the Savannah Harbor Expansion Project[24] in its expansion of the Savannah Harbor shipping channel from a depth of -42 feet to -47 feet.[25] He also authored the Email Privacy Act with Representatives Kevin Yoder and Jared Polis.[26] Graves led the national movement to defund the Patient Protection and Affordable Care Act ("Obamacare") in 2013.[20]

Graves and his wife Julie have three children and are active members of Belmont Baptist Church in Calhoun, Georgia.[31]

In 2011, Graves and a business partner (state Senate Majority Leader Chip Rogers) were accused of defaulting on a $2.2 million bank loan for a real estate investment. Attorneys for Graves argued that the bank had been at fault for loaning him money that they knew he couldn't repay, making the signed personal guarantees invalid. Graves and his partner were no longer involved with the company used to take out the loan after transferring ownership to another party in 2009.[32] The new owner (the hotel's former manager) agreed to purchase the company and its real estate and debt from Graves and Rogers for $10,000 but says they never actually required him to pay them anything.[33] The default on Graves' loan contributed significantly to the collapse of the Bartow County Bank (the small community bank which loaned the $2.2 million to Graves). The bank's collapse and liquidation cost the Federal Deposit Insurance Corporation $69.5 million. According to Morgan Akin (the former bank chairman), he only approved the loan to Graves and Rodgers because, "They were well-respected members of the community, and we took that into account," and he never imagined such prominent political figures would default.[34] Furthermore, although Graves and Rogers claimed the new owner of the company only defaulted on the loan because the bank reneged on a promise to refinance, the bank countered that the loan was in default before the sale of their company and they invalidated their refinancing deal because they sold the company without informing the bank. In August 2011, the bank's dispute with Graves was settled out of court and no details of the settlement were disclosed.[35][36] Due to unpaid property taxes going back to 2009, the city may have to seize the property and spend over $100,000 to secure and eventually demolish it.[37]